Adhesive tapes and adhesive labels each of which comprises a substrate in the form of a tape, a film or etc. and an adhesive layer formed on the substrate are conventionally known.
Examples of the adhesive tapes include a single-sided adhesive tape comprising a release agent layer formed on one surface of an adhesive tape substrate and an adhesive layer formed on the other surface of the substrate; and a double-sided adhesive tape comprising a double-sided adhesive tape main body which has an adhesive tape substrate bearing adhesive layers on both surfaces thereof and a double-sided release tape having a release tape substrate bearing release agent layers on both surfaces thereof, which adheres to one of the surfaces of the adhesive tape main body.
The adhesive tapes are stored or on the market as rolls formed by winding those tapes around a paper core or a plastic core. In the case of the single-sided adhesive tape, the adhesive tape itself is rolled up via its release agent layer so that the adhesive layers are not directly brought into contact with each other. In the case of the double-sided tape, the double-sided adhesive tape main body is rolled up via the release tape so that the adhesive layers are not directly brought into contact with each other.
Examples of the adhesive labels include an adhesive label which comprises an adhesive label main body having an adhesive label substrate and an adhesive layer laminated thereon and a release sheet having a paper sheet and a release agent layer provided thereon, in which the adhesive layer of the adhesive label main body is adhered to the release agent layer of the release sheet.
For the use of the adhesive label of this type, the adhesive label main body is released from the release sheet.
As the substrates of the adhesive tapes and the adhesive labels referred to the above, plastic substrates have been mainly used conventionally. For the disposal of the conventional adhesive tapes and adhesive labels after use, they are incinerated or buried in the soil.
However, such disposal involves the following problems.
(1) Problems in disposal by incinerating.
When the adhesive tapes and adhesive labels including the plastic substrate are incinerated, energy of high intensity is required for burning the plastic substrate. Further, carbon dioxide is generated by burning of the plastic substrate, and thereby warming of the earth may be accelerated. Particularly when the plastic substrate is polyvinyl chloride, a hydrogen chloride gas is generated to cause acid rain.
(2) Problems in the disposal by burying in the soil.
Recently, waste disposal by burying the waste in the soil has been markedly increased, and hence it is difficult to keep a site for the waste disposal. Further, if the adhesive tapes and the adhesive labels are buried in the soil, the plastic materials used for their substrates stably exist for a long period of time, and thereby the natural environment is disrupted or the ecosystem in the soil is disorganized.
It can be thought to separate the plastic substrates from the adhesive tapes and the adhesive labels after use to recycle them. However, the separation and the collection of the plastic substrates require an enormous cost, and this results in bad marketability. In addition, such recycled plastic substrates are deteriorated in quality.